help getting pulley on shaft

[eljefino]

7 hp tecumseh horizontal shaft tiller blew up, moved a spare motor over; had different pulleys so had to swap those.

Donor motor's unusable pulley came off clean.

Proper pulley's allen screw heads stripped out when the screws jammed in place. I got the evil thing off with a jaw puller. I may have gotten a couple turns loose on one of the two, the one not by the key. This is a heavy complicated pulley with 4 forward 3/8" belt slots and a reverse. Think it's cast iron. ~30 year old airens tiller FWIW.

Pulley slid on the new motor dandy, took a few hammer taps, nice and snug. Took it for a test run and it came spinning off and, when hitting the driveway with lots of centrifugal force, tore off like a rabbit.

So I need to stick it on there better.

-- Drilling the old screws out for repairs looks like a major pain-- hardened screw in softer pulley material, nearly an inch deep threads, etc.

-- I have a stick welder but think the pulley might be cast iron, compared to the steel motor shaft, and this presents a major challenge. I could braze but have no gear for that and might as well just buy a new pulley if I want to spend the money.

Any ideas I haven't thought of???

 

[Steve S]

Drill and tap some new holes?????

 

[labman]

When I was an industrial manager, we Lock-Tited about a 6 belt pulley on a 92 horse mixer motor and ran it that way for years. I know we did the same with a 25 horse air compressor flywheel and maybe a 100 horse one.

 

[eljefino]

I like the way you think labman! Loctite better than JB weld? Thinner perhaps?

 

[greenaccord02]

I would think there has to be an adhesive that would fir the need. One of the types of Loctite would probably do very well. Done forget to lightly score both surfaces for the best grip.

 

[JimPghPA]

There are several types of Loctite. In general Loctite will require you to use the same amount of torque to remove a bolt or nut that you used to assemble it, regardless of the amount of time or the vibrations it was exposed to.

However, there is one Loctite that will essentially weld metal parts that have a close fit. It is Loctite 680 Retaining Compound. It is used for cylinder liners, valve seats, and anything you want to put together with a snug fit that you NEVER want to EVER get apart again. You have to heat it to 482 Fahrenheit and pull it apart when it is still hot to get it apart.

If you want it to stay together get some Loctite 680 and clean both parts with alcohol, and blow dry with a hot air gun or hair dryer before assembly. Give it a day to get to full strength. If you can it helps to heat it to 100 Fahrenheit for one hour, but it will get to at least 50 percent strength in 24 hours without heating and that is plenty strong enough.

Google "Loctite 680" for the data sheet.

One nice thing about it is that a small bottle of it has a very long shelf life. Use a pin in the hole you put in the top and reinstall the pin for storage.

Good Luck.

JimPghPa

 

[JimPghPA]

Napa can probably special order it, or go to McMaster Carr web site.

JimPghPa

 

[labman]

Originally Posted By: eljefino
I like the way you think labman! Loctite better than JB weld? Thinner perhaps?


Since we never tried JB, I won't say. It was all about 25 years ago, so I would trust the details others have provided.

 

[greenaccord02]

I've tried them both and for what you're trying to do I think locktite is the better of the two. Jim's recommendation seems to be just what you need.

 

[doitmyself]

That might be a 15 minute repair for a machine shop...$20 maybe???
At least check it out.

 

[yeehaw1960]

Do it right and it won't fly off and bonk your kid or grand kid in the head. Drill them out with a small drill bit and use an easy out to remove them. Do things half a*sed gets people hurt. Kind of preachy huh?

"Yup! That old pulley bounced down the sidewalk, busted through the kitchen window and killed my wife...honest!"